Another vote for the Maxpedition Keyper . I've been using the same one daily for over a year, and it'd holding up GREAT.

It keeps my keychain tools- including, but not limited to: Atwood whistle, TnC AAA flashlight, Sliver Grippers, Magnesium rod, pill capsule, and sometimes a Spyderco Jester- from falling to the bottom of my pocket. Sometimes some keys too <img src="/images/graemlins/cool.gif" alt="" />